Edit/Write tools fail with EPERM on Windows drive root paths (e.g. D:\)

Description

The Edit and Write tools fail when operating on files located at the root of a Windows drive (e.g. D:\windows_watermark_v6.py).

Error

EPERM: operation not permitted, mkdir 'D:\'

Steps to reproduce

1. Place a file at a Windows drive root, e.g. D:\example.py
2. Attempt to use the Edit or Write tool on that file
3. The operation fails with the above error

Expected behavior

The tools should handle drive root paths correctly on Windows, since the directory already exists.

Actual behavior

The tools internally attempt to mkdir the target file's parent directory. When the parent is a drive root (D:\), the OS rejects the mkdir call with EPERM because drive roots already exist and cannot be "created."

Workaround

Using Python's open() via the Bash tool to write files at drive roots works fine, since it doesn't attempt to create the parent directory.

Environment

• Windows 11 Enterprise 10.0.26200
• Claude Code CLI with Bash shell